Another coincidence problem for $\Lambda$CDM?

TL;DR

This paper examines a recent coincidence problem in the $\\Lambda$CDM model related to the Universe's age and deceleration parameter, and shows that Planck data resolves this issue with high confidence.

Contribution

The paper demonstrates that the Planck cosmological data removes the coincidence problem present in earlier WMAP results within the $\\Lambda$CDM framework.

Findings

Planck data shifts cosmological parameters compared to WMAP.

The coincidence problem is statistically resolved with Planck data.

The analysis supports the consistency of $\\Lambda$CDM with current observations.

Abstract

Over the last nine years of cosmic microwave background observations, the Wilkinson Microwave Anisotropy Probe ($WMAP$) results were consistent with a $\Lambda$CDM cosmological model in which the age of the Universe is one Hubble time, and the time-averaged value of the deceleration parameter is consistent with zero. This curious observation has been put forward as a new coincidence problem for the $\Lambda$CDM concordance cosmology, which is in fact a `greater' coincidence than the near equality of the density parameters of matter and the cosmological constant. At the moment of writing these conference proceedings, the Planck Collaboration has released its first cosmological data, which revealed a small shift in the $\Lambda$CDM cosmological parameters when compared to $WMAP$. We show that under the assumption of a spatially flat $\Lambda$CDM cosmology, Planck's results remove this coincidence problem for $\Lambda$CDM at greater than 99\% confidence level.